Electrical regulator



y 1947. c. c. HONEYWELL 2,424,464

ELECTRICAL nmuu'roa Filed April 26, 1945 glmrlascmgwll Patented July 22, 1947 ELECTRICAL REGULATOR Charles signor Clinton Honeywell, New Milford, N. J asto Bendix Aviation Corporation, Teter- Mn, N. 1., a corporation of Delaware Application April 26, 1945, Serial No. 590,374

The present invention relates to electrical resulators and more particularly to a novel electrical system whereby hunting of the regulator may be reduced and a controlled voltage maintained at a desired value.

4 Claims. (Cl. 171-229) An object of the invention is to provide in a voltage regulating system, novel electrical means for effecting stability of control.

Another object of the invention is to provide novel means for eflecting anti-hunt characteristics in a voltage regulator.

Another object of the invention is to provide in an electromagnetically operated variable resistance device for regulating the output of a generator, novel means connected across the resistance device for utilizing changes in the resistance thereof for providing a follow-up action retarding further change.

Another object of the invention is to arrange in a regulator of the carbon pile type,a transformer having its primary winding connected across the carbon pile and its secondary winding in circuit with an electromagnetic winding for controlling the carbon pile so as to provide, upon change in the resistance of the carbon pile, a follow-up action tending to retard adjustment of said carbon so as to prevent over adjustment of the carbon pile and hunting of the regulator.

Another object of the invention is to provide a novel temperature responsive element for governing the follow-up action.

Another object of the invention is to provide a novel resistance element for compensating the regulator for changes in temperature.

Another object of the invention is to provide the latter temperature compensating resistance element in circuit with the secondary winding of the aforementioned transformer so as to P e circuit in parallel with the control winding which compensates for changes in the resistance of the control winding due to changes in temperature and also effects a follow-up action for maintaining stability in the regulator.

Theseand other objects and features of the invention are pointed out in the following description in terms of the embodiment thereof which is shown in the accompanying drawing. It

is to be understood, however, that the drawing is for the purpose of illustration only, and is not designed as a definition of the limits of the inven- '2 tlon, reference being had to the appended claims for this purpose.

The drawing is a diagrammatic view illustrating an electrical system embodying one form of my invention.

In the form of the invention shown in the drawing there is provided a direct current generator of conventional type and indicated generally by the numeral I.

The generator I has an armature winding. not shown, but which may be of conventional type. Connections from the armature winding lead to a suitable commutator having brushes 2 and 3 and output lines 4 and 5 leading from the brushes to lines 6 and I which lead to a variable load indicated generally by the numeral 8. The armature is driven by a suitable power source, not

shown.

The generator I has a suitable field winding 9 having one end thereofconnected by a conductor 9A to the line 5.

The opposite end of the field winding 8 is connected by a conductor 10 to one end of a variable resistance carbon pileelement H. The opposite end of the carbon pile II is connected through conductor II, to the output line 5. Thus the carbon pile ll controls the energization of the field winding 9 which in turn controls the output of the generator I in a manner well known in the art.

The carbon pile ii forms one element of a carbon pile regulator shown diagrammatically in the drawing as including an armature l3 pivoted at M and exerting a compressive force upon the carbon pile ll under tension of a spring l5. The position of the armature I3 is controlled by an electromagnet it having a core and exerting an electromagnetic force acting in opposition to the spring IS. The spring i5 is so arranged as to balance the pull on the armature Why the electromagnet I6 when the electromagnet I8 is energized by a voltage having a predetermined value. The regulator is preferably of a type such as shown in the copending patent application Serial Number 570,002 of William G. Nelld, filed December 27, 1944.

One end of the electromagnetic winding i8 is connected through a conductor I! to the output line 4. The opposite end oi the electromagnetic 3 i winding I6 is connected through a conductor I! to one end of a ballast resistor I9.

The resistor I9 is connected through an electrical conductor 20 to the conductor I2 and thereby to the output line 5.

Thus it will be seen, that the electromagnet IE will be energized in response to the output voltage across the lines 4 and 5. Moreover, a change in such voltage will cause an adjustment of the armature I3 so as to cause a corresponding adjustment of the carbon pile H to maintain a substantially constant output voltage in the lines 4 and 5.

In such a system due to changes in load or driven speed of the generator the regulator in attempting to follow such changes will tend to approach instability due to hunting of the regulator.

An object of my invention therefore is to provide an anti-hunt circuit whereby an electrical follow-up action is introduced into the regulator system. This is accomplished by providing a transformer 2| including a high tension primary winding 22 and a low tension secondary winding 23. The primary winding 22 is connected at opposite ends to the lines I and I2 and thus across the carbon pile I I,

The secondary winding 23 is connected at one end by a conductor 24 to the line I8, and at the opposite end by a conductor 25 to a resistor element 26 for a purpose which will be described hereinafter. The resistor element 28 is connected at the opposite end by a conductor 27 to the conductor IT,

From the foregoing it will be seen, that the voltage applied across the primary winding 22 will be the same as that across the carbon pile I I. Moreover, as the resistance of the carbon pile II is varied in response to change in the voltage across the lines 4 and 5, a corresponding change in the voltage drop or fall of potential across the carbon pile II is effected. This in turn causes the voltage applied across the primary winding 22 of the transformer 2| to change effecting an induced voltage in the secondary winding 23. The secondary winding 23 is connected in circuit with the control winding I6 through electrical conductors 24, 25, resistor 26 and conductor 21 so as to form a closed circuit and is so arranged that the momentary voltage induced in the winding 23 by change in the voltage drop across the carbon pile II tends to act upon the eletromagnetic winding I6 so as to retard or limit further change in a like direction. Thus the voltage induced in the winding 23 upon an increase in the voltage across the resistance II, as upon an increase in the resistance of the carbon pile II, acts in opposition to the flow of current through winding I6 from the output lines 4 and of the generator I. The thus induced voltage in acting through the winding Ili tends to oppose an increase in the magnetic field created by the current under the voltage across the output lines 4 and 5. The induced voltage in winding 23 thus momentarily tends to oppose further change in the position of the armature I3 in a resistance increasing direction.

Likewise upon a decrease in the resistance of the carbon pile I I causing a decrease in the voltage applied across the primary winding 22, there is induced in the secondary winding 23 a voltage and a, resulting current which flows in a direction through the winding I6 tending to momentarily augment the energizing current in the winding I6 from the output lines 4 and 5. The indlwed current in winding 23 thus momentarily tends to oppose further change in the position 01 the armature ii in a resistance decreasing direction.

In the operation of the latter arrangement, it will be seen that the transformer 2| connected across the carbon pile II will respond to change in the resistance of the carbon pile II so as to effect a follow-up action tending to prevent the carbon pile II from over adjustment.

Thus upon an increase in voltage across the output lines 4 and 5, the energization oi the electromagnetic winding I6 will be increased adjusting the armature I 3 against the tension of the spring IS in a resistance increasing direction. Moreover, upon such increase in the resistance of the carbon pile II, the voltage applied through the transformer 2| on the electromagnetic winding I6 during such change will tend to decrease the magnetic field of the winding I! and thereby effect a follow-up action tending to prevent over adjustment of the carbon pile in a resistance increasing direction.

01 course, upon a decrease in the voltage across the output lines 4 and I, an opposite effect will result so that energization of the electromagnetic winding I 6 will be decreased, causing the spring I5 t bias the armature I3 in a resistance decreasing direction. The latter action will cause the voltage applied through the transformer 2| to tend to increase the magnetic ileld of the electromagnetic winding II so as to thereby efiect a followup action tending to prevent over adjustment of the carbon file in a resist ance decreasing direction.

Thus there will result an electrical follow-up action in response to change in the resistance of the carbon Iplle II for momentarily limiting, opposing and retarding adjustment of the carbon pile I I in a, resistance increasing or resistance decreasing direction. The latter arrangement will thereby prevent over adjustment of the carbon pile II and hunting of the regulator.

There is further provided in the latter followup circuit a resistor 26 which may be positioned adjacent or about the winding of the regulating coil I6 so as to be subject to substantially the same temperature effects as the regulating coil I 8.

The resistor 26 is formed of a material having a greater temperature coefllcient of resistance than the material of the regulating coil I6 and the resistor 26 is so arranged that the combined resistance of the secondary winding 22 and the resistor 26 vary at a greater rate than that of the coil I8 over the ordinary expected range of temperature changes so that upon an increase in the temperature at the coil I. increasing the resistance thereof, the resistance of the resistor 22 adjacent thereto will also increase, but at a greater rate so as to decrease the shunting effect of the secondary winding 23 plus resistor 26 so as to compensate for changes In the resistance of the coil it due to such increase in temperature.

Likewise upon a decrease in temperature the resistance of the coil I8 will decrease, together with the resistance of resistor 20. The resistance of the resistor 26 will decrease at a greater rate so that the shunting effect of the secondary winding 22 plus resistor 28 will increase so as to compensate for the decrease in the resistance of the resistor 28 due to such decrease in temperature.

In further explanation of the operation or the material having a substantially zero temperature coemcient of resistance and leads from the generator output line S'through coil winding i6 to the output line 4. Extending in parallel to the winding i6 is the winding 23 and resistor 26. The winding 23 is arranged so that the resistance thereof is substantially unefiected by such temperature change. However, since the resistance of the resistor 26 increases with the rise in temperature more rapidly than the resistance of coil I6, it will be seen that upon such a resulting increasein the voltage drop across the resistor 26' .plus winding 23 there will be effected an increase in the voltage applied across coil i6. The resistor 26 is so arranged that the corresponding increase in the voltage across the coil I6 will in effect compensate for the increase in the resistance of the coil i6 due to rise intemperature. A corresponding compensating action will be effected upon a decrease in temperature.

Moreover, while the resistor 26 is shown as connected in series with the secondary winding 23 it will be-readily apparent that if desired the transformer 2| may be omitted in which case the resistor 26 may be connected solely in parallel to the coil 16 so as to accomplish the desired temperature compensation.

Likewise, if desired, the temperature compensating means 26 may be omitted so as to provide follow-up action solely. In the arrangement shawn in the present invention, however, in which the variable resistance means 26 is provided in series with the secondary winding 23 of the follow-up transformer 2 i not only is the coil I6 compensated for temperature changes, but the followup action of the secondary winding 23 is likewise temperature compensated.

Thus as the resistance of the coil l6 increases upon a rise in temperature causing a corresponding decrease in the sensitivity of the coil [6, the resistance of the temperature responsive element 26 likewise increases so as to decrease the intensity of the follow-up action on the coil l6, while increasing the duration thereof so as to provide a follow-up action more in accordance with the condition of the regulator coil l6.

Similarly at lower temperatures at which the resistance of the coil i6 is less and the sensitivity of the coil i6 greater, the intensity of the electrical follow-up impulse is greater so as to provide a sharper follow-up action under greater sensitivity conditions of the coil I6.

Thus it will be seen that there is providedherein anovel follow-up means which is temperature compensated so as to provide an electrical follow up impulse of greater intensity under temperature conditions at which the regulator coil II has greater sensitivity and a follow-up electrical impulse of less intensity under temperature conditions at which the regulator coil II has less sensitivity.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangements of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention. Reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. In a regulating system for a. generator of the type including a field winding for controlling a condition of the output of said generator, first means electrically connecting said field winding in series with a first variable resistance element,

said first resistance element and-fleld windin connected across the output of said generator, an electromagnetic winding, regulating means for said variable resistance element, said regulating means operatively controlled by said electromagnetic winding, a second resistance element, second means electrically connecting said electromagnetic winding and the second resistance element in series, said electromagnetic winding and second resistance element connected across the output of the generator; the combination comprising a transformer including a primary winding and a secondary winding, the primary winding connected across the variable resistance element, a resistor positioned adjacent said electromagnetic winding, said resistor having a greater temperature coefllcient of resistance than said electromagnetic winding, said resistor connected in series with said secondary winding across the electromagnetic winding so as to compensate for changes in the resistance of said electromagnetic winding due to temperature and so arranged as to cause upon change in the resistance of said variable resistance element an electrical impulse to effect said electromagnetic winding so as to prevent hunting of the regulating means.

2. In a regulator of the type including a variable resistance element, .and an electromagnetic winding for controlling said variable resistance element; the combination comprising an inductive coupling means including a first winding connected across said variable resistance element and a second winding connected across said electromagnetic winding so that changes in the resistance of said element will cause a change in the current flow in said first winding so as to induce a follow-up voltage in said second winding, said second winding including a circuit so arranged that said follow-up voltage acts in such a manner as to effect said electro-' magnetic winding so as to prevent hunting of the regulator, and an electrical resistor means in which. the electrical resistance is variable in response 'to changes in temperature, said resistor means connected in said second winding circuit so as to adjust the voltage drop across said electromagnetic winding so as to compensate for changes in the resistance of said electromagnetic winding due to such changes in temperature and said resistor means also so arranged as to vary the intensity of said follow-up voltage so as to provide a follow-up action of greater intensity under greater sensitivity conditions of the electromagnetic winding.

3. In a regulating system fora generator of the type including a variable resistance element for regulating a condition of the output of said generator, and electromagnetic means for controlling said variable resistance element and responsive to an electrical condition oi. the output ofsaid generator; the combination comprising electrical follow-up means arranged in such a manner that upon a change in the resistance of said element in one sense there will be applied a voltage to said electromagnetic means for retarding the adjustment of said resistance element by said electromagnetic means in said one sense, and temperature responsive means connected in circuit with said electrical followup means and in series relation with said electromagnetic means for varying the intensity of said follow-up voltage in accordance with temperature conditions eflecting the sensitivity of saidelectromagnetic means.

4. In a regulator, the combination or means for controlling a variable condition, means for operating said controlling means in response to changes in said variable condition, the sensitivity of said operating means being variable with temperature, means for eflecting a follow-up action upon a change of said controlling means, said follow-up means being arranged to partially oppose .the stated change or said controlling means by said operating means, and temperature responsive means governing said follow-up action in accordance with temperature conditions to provide an increased follow-up action under reater sensitivity conditions 01' the operating means.

CHARLES CLINTON HONEYWELL.

REFERENCES CITED The following references are of record in the. tile of this patent:

UNITED STATES PATENTS 

